Living with Wildlife PACIFIC TREEFROG (Pseudacris regilla) Facts about Pacific Treefrogs Benefits of Treefrogs Habitat Food and Feeding Habits Reproduction and Life Cycle Preventing Conflicts Attracting Treefrogs Species Status and Wildlife Laws More Information Pacific Treefrog Photos by Kelly McAllister FACTS ABOUT Pacific Treefrogs killers and roof treatment chemicals can also be toxic, and often The Pacific Treefrog (Pseudacris regilla) is the smallest and most such runoff is directly channeled into wetlands via pipes or commonly seen and heard frog in Oregon. It has several common sewer outflows. names Northern Pacific treefrog, Northwest chorus frog and Pacific l Control nonnative plants such as reed canary grass that degrade chorus frog. the quality of wetland and upland habitats. Use hand control Adult treefrogs measure two inches in length and vary in color from a and mechanical methods to control small patches of invasive bronze brown to a light lime green. They have two distinctive features: vegetation. a dark stripe across each eye and rounded toe pads. Males also have a l Remove nonnative predators such as the American bullfrog and dark throat patch. This frog stays moist because glands in its skin secrete common snapping turtle, which are both classified as Nonnative a waxy coating. The chorus or call of the male treefrog is a loud, two- Prohibited Wildlife species and are on ODFW’s list of part kreck-ek, or a rabbit. It is often repeated many times in an effort to 10 Most Unwanted Invasive Species. attract females for breeding. This calling stimulates other males to join l Never release a bullfrog or other non-native wildlife into the in, and large concentrations of these frogs can be heard from far away. wild—it’s unlawful. If you are an educator, find a copy of Male treefrogs call mainly in the evening and at night, although they Wildlife in the Classroom in the invasive species section also call sporadically during the day at the height of the breeding season. of ODFW’s Web site. Male frogs may call any time of year (when they are not courting or l When designing a backyard pond, locate it away from bedrooms hibernating) from dry upland sites. This is heard as a single-note croak yours and your neighbors—spring can bring a short-lived but noisy “Krr-r-r-ek“ ( ) and typically occurs when air humidity is high. This type chorus of male treefrogs. of call is believed to be a type of territorial call. Habitat Benefits of Treefrogs Treefrogs live in wetlands, meadows, woodlands and brushy areas. Treefrogs and many other native frogs and toads in Oregon are on the They breed in shallow ponds, slow moving streams, seasonal pools, decline and need our help. Frogs are an important component of a watering tanks and roadside ditches. Breeding sites are used only healthy ecosystem. They eat insects and slugs around ponds, streams, a few weeks or months of the year. Treefrogs spend the rest of the homes and gardens, and they are sources of prey for other wildlife. You year in surrounding upland areas. In fact, it is not uncommon to can help by managing your property in a frog-friendly manner. find treefrogs several hundred yards from water. During dry periods l Avoid using pesticides and herbicides. Amphibians have highly and in arid areas, adult treefrogs are active only at night, spending permeable skin that can absorb toxic chemicals. They can be poisoned the day in water or shaded vegetation, rocks or log crevices, rodent directly or indirectly through their food, such as slugs and snails. Moss- burrows or other protected places. Oregon Department of Fish and Wildlife Twelve native species of frogs and toads live in Oregon. Many of them are classified as Oregon State Sensitive species and listed in the Oregon Conservation Strategy as species in need of help–that means they have small or declining populations. Worldwide, frogs are in trouble and many are on the road to extinction. Habitat loss, pollution, pesticides, climate change, infectious diseases, the pet trade and invasive species are all causing problems for frogs. To learn more, visit the Living with Wildlife Section of the Oregon Department of Fish and Wildlife website. Food and Feeding Habits Attracting Treefrogs Toe pads on treefrogs’ front and hind toes enable them to climb in For those who love treefrogs, there are a number of things that you can search of food—beetles, flies, spiders, ants and other invertebrates. Adult do to attract frogs to your property. treefrogs catch their prey with long, elastic-like, sticky-ended tongues. l Protect existing natural areas. Treefrog tadpoles eat algae and decaying vegetation and scavenge on Woodlands, wetlands, meadows, stream corridors and shorelines attract frogs and other wildlife. dead earthworms, fish and insects. l Protect buffer areas next to streams, lakes or ponds. Vegetated buffers Reproduction and Life Cycle protect the ecological functions and value of the breeding habitat and Depending on location, treefrogs move into aquatic breeding sites from provide needed upland habitat. February to July. Male treefrogs move first and vocalize in early spring l Protect movement paths between uplands and breeding sites. If you have a through early summer to attract females. They chorus while floating at roadway through your property, install amphibian crossing structures, the surface or sitting partially submerged in shallow water. Females lay such as small tunnels under it. Amphibian movements can also be 400 to 750 eggs, which are externally fertilized by the male. Individual guided by means of large logs, brush piles and other ground material egg masses contain 10 to 75 eggs, measure one to two inches across that retains moisture and provides cover. (usually about half the size of a tennis ball) and are surrounded by a l special jelly that swells up on contact with water. Egg masses are attached Leave a portion of your grass unmowed, especially in areas that adjoin to sticks or emergent aquatic vegetation just below the surface, and often a wet area, forest edge or any area that is being used by amphibians. become camouflaged with algae and sediment. Eggs hatch more quickly If you must mow in these areas, scout the area for amphibians and in warmer water in three to five weeks. The tiny hatchlings soon turn mow at slower speeds to give them time to move out of the way. Set into tadpoles with short, round bodies and eyes that bulge out at the the mower blades as high as possible, or use a weed-whacker and leave sides of their heads. In eight to 10 weeks, metamorphosis is complete grass six inches high. Be particularly mindful during breeding and when the tadpoles change into 1/2-inch long, air-breathing juvenile juvenile dispersal periods. frogs that climb onto land and eventually return to water to breed. Treefrog populations can fluctuate dramatically from year-to-year; frogs may not breed at all if the rainy period of the year is too short. Like many other species of amphibians that produce large numbers of eggs, most treefrogs die at the egg or tadpole stage. Treefrog eggs are eaten by caddisfly larvae and fish. Fungus and frost also kill some eggs. Tadpoles are eaten by dragonfly larvae, diving beetles, fish, long-toed salamander larvae, bullfrogs, garter snakes and birds (herons, ducks, and jays). On land and at the water’s edge, raccoons, foxes, coyotes, river otters, skunks, snakes, hawks and owls eat adult treefrogs. Unnatural factors also take their toll on treefrogs cats, children, lawn mowers and vehicles add to treefrog mortality. The loss of wetlands, the clearing of adjacent upland areas, and pesticides negatively affect treefrogs. Treefrogs that do reach adulthood live an average of two years in the wild. Preventing Conflicts The most common complaint about treefrogs is that they are noisy. While many people enjoy them as the first sounds of spring, some find the chorus of male treefrogs annoying. If ear-plugs don’t work for you, the best solution is to eliminate the reason treefrogs are attracted to your yard. In other words, make modifications to whatever the frogs are using to make the area less attractive to the frogs. For example, empty or seal off unused swimming pools and drain water from pool covers. Remove other cover such as flower pots and wood piles. While there is no fence that will keep treefrogs out of your yard, you may be able to keep frogs out of a small pond by covering it with fine mesh that has holes smaller than the frogs themselves. You can also add fish or a pump to circulate pond water and create turbulence. Many frogs will not breed in pond with fish. Note: Due to concerns about nonnative invasive species, no fish should ever be added to a pond that is connected to a natural waterbody, a stream or wetland. Repellents and The “rib-it” call of male Pacific treefrogs is often heard on scare devices do not work on frogs and no poisons should ever be added movie soundtracks. to the water. l Preserve leaf litter under trees and shrubs. Such material provides MORE INFORMATION cover and moisture; it also attracts organisms that amphibians eat. Oregon Department of Fish and Wildlife l Retain stumps, logs, root wads, rock piles and other debris that provide a cool, moist habitat for amphibians. Such habitat features ODFW: Amphibian Species of Oregon provide much needed cover. All these can be strategically located ODFW: Facts for Kids: Frogs are cool (PDF) as “stepping stones” across exposed areas, or to bridge gaps ODFW: Living With Wildlife between breeding ponds and woods.